DCB consists of the following 802.1 draft standards that specify how networking devices can interoperate within a unified data center fabric:

Priority-based Flow Control (PFC)
PFC is specified in the IEEE 802.1Qbb draft standard. This standard is part of the framework for the DCB interface.

PFC supports the reliable delivery of data by substantially reducing packet loss due to congestion. This allows loss-sensitive protocols, such as FCoE, to coexist with traditional loss-insensitive protocols over the same unified fabric.

PFC specifies a link-level flow control mechanism between directlyconnected peers. PFC is similar to IEEE 802.3 PAUSE frames but operates on individual 802.1p priority levels instead. This allows a receiver to pause a transmitter on any priority level.

Enhanced Transmission Selection (ETS)
ETS is a transmission selection algorithm (TSA) that is specified in the IEEE 802.1Qaz draft standard. This standard is part of the framework for the DCB interface.

ETS allocates bandwidth between traffic classes that are assigned to different IEEE 802.1p priority levels. Each traffic class is allocated a percentage of available bandwidth on the data link between directlyconnected peers. If a traffic class doesn't use its allocated bandwidth, ETS allows other traffic classes to use the available bandwidth that the traffic class is not using.